In comparison to conventional spur gearings and combined bevel and spur gearings, planetary gear sets afford significant advantages in respect of power density and specific torque, and comprise a sun wheel, a planet carrier with planet wheels and an internally toothed ring gear. Planetary gear sets for industrial applications frequently have a cylindrical constructional form because of a cylindrical basic shape of the ring gears. Planetary gear sets may be mounted as slip-on gearings with a torque bracket, as screw-on or flange-mounted gearings or in a base arrangement with an additional frame.
Cast materials, such as ADI-900, which are suitable for toothings permit constructions in which housing parts and internally toothed ring gears are combined in an integral construction. A disadvantage in this case is that high-grade toothing material is uneconomically also used for housing elements which require less high-grade materials.
DE 10 2005 029 858 A1 discloses a gear set combination comprising a planetary stage and a spur gear stage and having a block-shaped housing. The housing is closed at the end face by a cover. In addition, a gear set housing with a cuboidal basic structure is described in U.S. 2008 045374 A1. DE 102 51 499 A1 describes a gear set combination with a modular construction for cascadeable planetary stages and with complementary flange zones on gear set housing sections.